Device for preheating during welding and method

Abstract

By the use of two lasers which are not mechanically connected to each other but the beams of which are then coupled to each other, it is possible to carry out preheating and remelting or melting in a very simple manner is provided.

1 - 8 . (canceled) 
     
     
         9 . A device for laser welding, having at least:
 one first laser,   one second laser,   wherein the laser beams of the first laser and the laser beams of the second laser are coupled together by means of an optical unit into one laser beam,   in which the laser beams of the second laser can be directed via a scanner and a dichroic mirror together with the laser beams of the first laser onto a component.   
     
     
         10 . The device as claimed in  claim 9 , in which the wavelength of the laser beams of the first laser is between 800 nm and 1000 nm. 
     
     
         11 . The device as claimed  claim 9 , in which the wavelength of the laser beams of the second laser is between 1000 nm and 1100 nm. 
     
     
         12 . The device as claimed  claim 9 , wherein the optical unit has a collimating lens and a focusing lens. 
     
     
         13 . A method for laser welding, in which in particular use is made of a device as claimed in  claim 9 , wherein a first laser beam for preheating is guided, together with a second laser beam for melting or remelting, over a component. 
     
     
         14 . The method as claimed in  claim 9 , which the wavelength of the laser beams of the first laser is between 800 nm and 1000 nm. 
     
     
         15 . The method as claimed in  claim 9 , in which the wavelength of the laser beams of the second laser is between 1000 nm and 1100 nm.